Natalie Wood Death Probe: Cops Question Christopher Walken Over What REALLY HAPPENED On The Boat — Robert Wagner Still Refuses To Talk

More than thirty years after the mysterious death of Natalie Wood, the world is growing closer to finding out the truth about how she died.

Just one week after The National ENQUIRER exposed new claims that Wood discovered husband Robert Wagner and Christopher Walken in a gay clinch before her passing, RadarOnline.com has exclusively learned that Walken has secretly cooperated with investigators — but Wagner still refuses!

"After the investigation was reopened​ in 20011, Christopher Walken did sit down with detectives at least two times,” a law enforcement source told Radar.

"The interviews were brief, because he had no new information to reveal, but it was greatly appreciated that he took the time to do it. Mr. Walken also let it be known that if more questions needed to be answered, he would be willing to sit down again."

Wood died on November 29, 1981, when she drowned after a night on the yacht “Splendour” with Walken and Wagner. Initially, her death was classified as accidental drowning, but after the case was reopened in 2011, it was changed to “drowning and other undetermined factors.”

Meanwhile, boat captain Dennis Davern "has been interviewed multiple times by cops,” the insider said. "He was even taken out on a boat to the exact same area where the tragedy took place.”

"Dennis believes that Wagner was involved in Natalie's drowning,” the source continued. “But there are problems with Dennis as a witness because of substance abuse issues he has had in the past."

To this day, Wood's husband has repeatedly refused to be interviewed by investigators.

"Of course detectives would like to talk to Mr. Wagner about that night,” the law enforcement source insisted. "He is the only person on the boat that isn't dead that hasn't agreed to talk. There was information that was brought to the attention of investigators that caused the case to be re-opened. It still remains open."